Diagnostic imaging method

ABSTRACT

A method of identifying injury to soft connective tissues in complicated body joints deploys use of motion x-ray images as the joint moves to identify suspected abnormal pathology followed by Dynamic Upright MRI images of the joint under conditions that express the abnormal pathology. The Dynamic Upright MRI parameters are based on the suspected pathology. The method is particularly useful in detecting disco/ligamentous and other injuries that often times will not be visualized on conventional recumbent MRI, or static x-rays.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority to the U.S. Provisional PatentApplication of the same title having application Ser. No. 61/038,775which was filed on Mar. 23, 2008 and is incorporated herein byreference.

BACKGROUND OF THE INVENTION

The present invention relates to radiological imaging, and in particularto methods of MRI imaging of soft tissue.

The limitations of conventional X-ray imaging in detecting anddiagnosing soft tissue injuries, that is structures other than calcifiedbone, is well known. Soft tissue, being much less dense than bone, haseither too low a contrast to be observed, or is obscured by the bonestructures, as the x-ray itself is a projected image in which x-rays areattenuated as they pass through the patient.

Magnetic resonance imaging (MRI) provides images of tissues notgenerally visible in x-rays, as well as bone. Rather than the imagesbeing a projection through the tissue and organ from the front to theback of the image plane, as in conventional x-rays images, like Computedtomography (CT), MRI can be obtained of thin slices at differentpositions and orientations in any plane. Further, MR has much greatersoft tissue contrast than CT making it especially useful inneurological, musculoskeletal, cardiovascular and oncological diseases.Unlike CT it uses no ionizing radiation. The scanner creates a powerfulmagnetic field which aligns the magnetization of hydrogen atoms in thebody. Radio waves are used to alter the alignment of this magnetization.This causes the hydrogen atoms to emit a weak radio signal which isamplified by the scanner. This signal can be manipulated by additionalmagnetic fields to build up enough information to reconstruct an imageof the body.

Magnetic Resonance Imaging while capable of imaging soft tissue, ascurrently practiced has numerous limitations in identifying soft tissueinjuries. While improvements in MRI scanning techniques have reduced theacquisition time, imaging is still a serial technique where a slice ofthe patient is imaged by precise positioning of a magnetic field and theimposition of gradients onto the slice. Thus, MRI has the advantage overX-ray in that surrounding structure is eliminated, while X-ray are aprojection, with denser tissue obscuring features in finer tissue.However, as one attempts to acquire a sequence of MRI imagesdynamically, with limited motion between them, the resolution isinherently reduced as the speed of acquisition is increased to acquireadditional frames.

Unfortunately, a failure to find soft tissue injuries by MRI frequentlyleads to incorrect diagnosis, or the assumption that the patient isexaggerating about the symptoms of pain and discomfort, or are of apsychological rather than physical origin.

It is now appreciated, in light of the present invention, that becauseMRI is so specific and sensitive soft tissue injuries are morefrequently missed than identified. The ability to know early on in apatient's injury on what exactly has been traumatized is likely toresult in better clinical outcomes for patients, and less risk offurther degeneration, progressive deterioration of a patient's conditionfrom neglect or inappropriate treatments.

It is therefore a first object of the present invention to provide forthe identification of soft tissue injuries that have been elusive tostatic conventional diagnostic imaging protocols.

It is a further object of the invention to avoid the waste of time andexpense on unreasonable treatments and diagnostic studies that are madewhen soft tissue injury is overlooked or not fully understood.

It is a further object of the invention to provide for the assessmentand evaluation of the soft tissue injuries in moving joints, and inparticular injuries to the cervical spine. The proper assessment andevaluation directs the treating Physician into the best treatment/careplan necessary to help the injured patient, to minimize future pain andprevent treatments that can increase pain or cause further injury.

SUMMARY OF INVENTION

In the present invention, the first object is achieved by providing amedical imaging method for joints in living creatures, the methodcomprising the steps of: acquiring a dynamic sequence of x-ray images ofat least one joint of a living creature over a range of motion,analyzing the dynamic x-ray image frames to identify positions andlocations with possible abnormal pathology, determining MRI parametersfor imaging the possible abnormal pathology in greater detail than thex-ray images, acquiring MRI images at positions and locations withabnormal pathology with said parameters.

The above and other objects, effects, features, and advantages of thepresent invention will become more apparent from the followingdescription of the embodiments thereof taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart of a first embodiment of the method

FIG. 2 is a flow chart of a second embodiment of the method

FIG. 3 is a sagittal neutral position MRI of the cervical spine of ahealthy patient naming most of the visible anatomy.

FIG. 4A is an x-ray of the cervical spine of the upright patient in aneutral posture frame while FIG. 4B is a photograph of the patient atthe time the frame in FIG. 4A was acquired and FIG. 4C is the sagitalMRI corresponding to the posture in FIG. 4A.

FIG. 5A is an x-ray frame of the cervical spine of the upright patientin a neutral posture frame while FIG. 5B is a photograph of the patientat the time the frame in FIG. 5A was acquired. FIG. 5C is the sagitalMRI corresponding to the posture in FIG. 5A

FIG. 6A is a frame of a dynamic x-ray sequence capturing the cervicalspine of the upright patient in a flexion posture while FIG. 6B is aphotograph of the patient at the time the frame in FIG. 6A was acquiredand FIG. 6C is the sagital MRI corresponding to the posture in FIG. 6A

FIG. 7A is a frame of a dynamic x-ray sequence capturing the cervicalspine of the upright patient in a flexion posture while FIG. 7B is aphotograph of the patient at the time the frame in FIG. 7A was acquired.FIG. 7C is the sagital MRI corresponding to the posture in FIG. 7A

FIG. 8A is a frame of a dynamic x-ray sequence capturing the cervicalspine of the upright patient in a extension posture while FIG. 8B is aphotograph of the patient at the time the frame in FIG. 8A was acquiredand FIG. 8C is the sagital MRI corresponding to the posture in FIG. 8A

FIG. 9A is an x-ray frame of the cervical spine of the upright patientin a neutral posture frame while FIG. 9B is a photograph of the patientat the time the frame in FIG. 9A was acquired. FIG. 9C is an axial MRIimage on the slice indicated on FIG. 6A

FIG. 10A is a frame of a dynamic x-ray sequence of the cervical spine ofpatient is in an upright posture capturing the right rotation of thehead, FIG. 10B is a photograph of the patient at the time the frame inFIG. 10A was acquired. FIG. 10C is an axial MRI image on the sliceindicated on FIG. 10A

FIG. 11A is an x-ray frame of the cervical spine of the upright patientin a neutral posture frame while FIG. 11B is a photograph of the patientat the time the frame in FIG. 11A was acquired. FIG. 11C is an axial MRIimage on the slice indicated on FIG. 11A

FIG. 12A is a frame of a dynamic x-ray sequence capturing the cervicalspine of the upright patient in a flexion posture while FIG. 12B is aphotograph of the patient at the time the frame in FIG. 12A wasacquired. FIG. 12C is an axial MRI image on the slice indicated on FIG.12A

FIG. 13A is a frame of a dynamic x-ray sequence capturing the cervicalspine of the upright patient in an extension posture while FIG. 13B is aphotograph of the patient at the time the frame in FIG. 13A wasacquired. FIG. 13C is an axial MRI image on the slice indicated on FIG.13A

FIG. 14 is a flow chart for a computer aided application of the process.

FIG. 15A is a plan section view to schematically illustrate anembodiment of an apparatus for carrying out the imaging process. FIG.15B is a schematic illustration of a method of posture tracking for usewith the inventive method.

DETAILED DESCRIPTION

Referring to FIGS. 1 through 14, wherein like reference numerals referto like components in the various views, there is illustrated therein anew and improved Diagnostic Imaging Method, generally denominated 100herein.

In accordance with the present invention, the inventive process 100 asshown in FIG. 1 comprises a first step 110 of acquiring dynamic x-raysequence of at least one joint of a living creature over a range ofmotion. In the first step, 110 x-ray images are continuously acquired indifferent views of the joint under investigation as the patient movesthe joint in the different direction of normal motion. It is generallypreferable the joint's are load bearing during all of the dynamic X-ray(step 110) and MRI imaging steps 140, however in some instances it mayprove useful to obtain non-load bearing images by either static ordynamic x-ray or MRI.

The next step 120 in process 100 is analyzing the dynamic x-ray framesto identify positions and locations with abnormal pathoanatomy. Thesubsequent step 130 in process 100 is Determining of MRI parameters i.e.(which may include one or more of slice orientation, slice thickness,spin sequence and patient positioning, as further described below. Thenext step 140 is acquiring MRI images under these parameters atpositions and locations with abnormal pathoanatomy with said parameters.

Various embodiments and results of the invention will now be illustratedwith respect to the diagnosis of patients that have suffered a painfulor other injury to the cervical spine, such as from a motor vehicleaccident (MVA). In step 110, one or more series of x-rays images areacquired while the patient stands upright and move their head in thedirections indicated by the technician, which generally include inaddition to neutral sagital images, a sequence of images in front toback flexion, extension and side to side movement. Axial views arerecorded during the front to back extension and flexion as well asanterior-posterior view is recorded during side to side motion. Thex-rays are acquired very rapidly so that the patient can move the neckat normal speed but each x-ray image frame will show a relative smallamount of motion with respect to the adjacent frames. As the patient isupright, the mass of the head places a load on the cervical spine.

Recent improvements in the digital acquisition of x-rays have enableddynamic x-ray imaging where the clinician is able to see the bonestructure in a joint as the patient moves, as well as capture a sequenceof digital images of the joint under study in real time. Presentlydynamic x-ray equipment is available from DMX Works, Inc., 4159-BCorporate Court Palm Harbor, Fla. 34683. Other means of digital x-rayimage acquisition are described in the following U.S. Pat. Nos.6,256,374 and 6,490,475, which are incorporated herein by reference.

In step 120, the full sequence of x-ray image frames acquired in step110 is then reviewed by a physician to identify which postures indicatethe most aberrant pathoantomy for positive findings of intersegmentaljoint dysfunction/instability. By aberrant pathoanotomy we mean posturesthat show an abnormal absolute and relative position of the cervicalvertebrae with respect to each other, causing dysfunction or instabilityof intersegmental joints.

Although these selected X-ray images do not reveal the soft tissuedamage itself they serve as a guide for subsequent MRI imaging, which ifcarried out according to the most preferred embodiment of the invention,will reproducibly reveal the actual soft tissue damage.

The next step 130 of determining the MRI conditions is based on thepatient specific biomechanic assessment of vertebra posture and anatomyof the surrounding soft tissue.

Soft tissue damage when detected by MRI is generally apparent eitherbecause the soft tissue is torn, thinned, scarred ormisplaced/disconnected. However, it has been discovered that thesechanges will generally not be apparent unless the MRI is acquired underthe conditions that indicated abnormal pathology in the motion x-rayimage series of step 110.

Hence, it is important in step 140 that the patient be positioned withnearly the identical posture during the MRI that indicated abnormalpathology in the motion x-ray frame selected in step 120 as showing theaberrant pathology.

Recent improvement in MRI technology, as disclosed in the following U.S.Pat. Nos. 7,196,519; 6,677,753; and 6,828,792; which are incorporatedherein by reference, have enabled commercial equipment for theacquisition of MRI in other than prone position, such as weight bearingposition or any positions of a joint over a range of motion. Suchequipment is currently available from Fonar Corporation 110 MarcusDrive, Melville, N.Y. 11747

Further, the proper areas of the tissue must be imaged. Because MRI isso precise in its ability to image sections of tissue, care must betaken to select the appropriate series of sections as well as acquirethe images under conditions in which the suspected damaged tissue willstand out from adjacent tissue so that the diagnosis can be obtained.That is the radiologist analyzing the MRI images must be able to look atthe right location to see the thinning, tears, scar or other damage tothe precise soft tissue to diagnose the injury and source of pain. Thisparticularly problematic because such damage may be present in any ofthe three dimensions the damaged tissues occupies and at anyorientation, thus it will be difficult to capture in a 2-dimensionalimage acquired by MRI. Hence, prior MRI studies of a patient that didnot show soft tissue damage can cause false negative results.

Thus, in order to overcome this difficulty it has been discovered thatspecific imaging conditions will accurately and reproducibly indicatethe aforementioned tissue damage. However, these imaging conditions arespecific to the pathology identified in the motion x-ray analysis ofsteps 110 and 120.

Table 1 discloses preferred combinations of MRI imaging modes andconditions in series of columns for the various cervical spine injuriescommon in MVA, as listed in the sequence rows.

The important imaging conditions listed in the first row of Table 1 isthe patient's position or posture, the MRI slice orientation and thespin sequence and analysis method used by the MRI machine to create thecontrast in the image. Generally, in all cases it is desirable toacquire MRI images under the conditions in the second row when thepatient is upright, rather than prone or recumbent with the neck in aneutral posture (not bent in any direction) other neck positions areflexing forward or extending backward or titled to the side or with themouth open. After these neutral posture images are obtained additionalimages are acquired according to the pathology identified in step 110,where the patient is placed in the same posture that resulted in thefinding of abnormal pathology in step 120.

MRI imaging parameters are MRI slice orientation (stack positioning),slice thickness (for optimal ligamentous, joint dysfunction assessment),spin sequence (to view soft tissue with sequences best used to revealsoft tissue pathology) and where to specifically look for the lesionwhich had been found on the initial Motion X-Ray study of step 110.

The MRI slice orientation and position is either axial (looking down thespine) or sagittal (looking at the spine in profile) as well as centeredon a particular bone or junction. Anterior to posterior view (AP) meansfacing the patient from the front so that the right and left sides arevisible.

The images must be acquired in specific planes or slices where theabnormal pathology is likely to be visible based on the initial x-raystudy. Generally, it is preferred that multiple slices are obtained;hence there is a need to determine the slice spacing and the number ofslices.

It is also generally preferred in the inventive method that an x-rayimage that shows the proper posture for the MRI images also be markedwith one or more lines that indicate the desired MRI section locations.Such images that contain these marking will be referred to as templates.It is further preferred that the template also include a visualphotograph of the patent that is recorded at the same instant the X-rayimage was recorded. It is preferred that these images are provided assmall inset images of reduced magnification at the corner of templatewhere it will not obscure important anatomical features.

Thus, in another embodiment shown in FIG. 2, an additional step 135 ofthe preparation of a template guided by motion x-ray findings is todirect MRI image acquisitions. The template may be in an x-ray imagethat is neutral sagital, flexion, extension and A-P open mouth bendingso that the MRI technician can position the patient at the same postureduring the MRI acquisition of step 140, as well as acquire the MRI's atthe designated slices.

The inventive technique is very effective and reproducible for severalreasons. Damage to soft tissue is more likely to be visible underpostural loads when the bone movement is abnormal. The abnormality ofbone movement will aid in identify the specific soft tissue anatomy thatmay be damaged. However, the MRI(s) must also be recorded underconditions that are likely to highlight the damage. These conditionswill depend on the location of the injury, as the surrounding structuremay have inherent low or interfering contrast under some MRI conditions.

Thus, FIG. 9A-13A illustrates such a template wherein the correspondingFIG. 9C-13C are the MRI images of a slices as marked on the template.

Further, imaging parameters also includes a spin sequences, which refersto the precise nature of the magnetic field resonance and decay that ismeasured. These conditions are well known by the acronyms T1, T2, PDI(proton density image) and the like as indicated in the table. EachImaging parameter causes different types of cervical or joint tissues toappear lighter or darker in the MRI such that the full detail of theanatomy likely to be involved in each type of pathology in the x-raysequence can be detected.

The T1 imaging mode reveals bone position and fracture, rim lesion,which is a tearing of a disk from attachment to vertebra body as well asdistention of cranial elements through the foramen magnum (opening inskull where spinal cord descends).

In contrast, T2 imaging mode reveal soft tissue, such as ligaments,spinal fluid, nerves, spinal cord, muscle tears, swelling and edema. FSE(fast spin echo) is a subset of the T1 and T2 modes.

Proton density images (PDI) or proton density weighted sequences imagingmode is specifically best suited to reveal ligaments in thecranio-cervical junction ie. (alar, transverse ligament, tectorialmembrane, posterior atlanto-occipital membrane and the like). Sliceorientation is very import to visualize the alar ligaments consistently.While the gradient echo image (GRE) mode is preferred for acquiringaxial (top down) disc images.

Generally, speaking under such appropriate imaging mode/spin conditionsnormal ligament are typically dark, and expands along their length orbreadth at constant and homogenous intensity and thickness. However, ifthe ligament is damaged, it may appear thin or disappear, if not show anactual tear.

Further, when tissue is damaged it attempts to heal by growing fibroticcells. However, the fibrotic cells being weaker and not as elastic asthe native tissue will in effect be scared, and are frequently visibleas lightened area of signal intensity along a dark and continuousligamentous structure. Sometimes the damaged ligament will thicken whereit rubs against a bone due to misalignment from damage to it or anotherligament. A few ligaments are particularly prone to such damage notbecause of initial injury, but because the failure of other ligamentsresults in their mal-positioning with respect to bone.

Thus the skilled radiologist, surgeon or chiropractor, when presentedwith the MRI images acquired under conditions in Table I will be utilizetheir intimate knowledge of normal soft tissue anatomy to recognize theabnormal tissue that is either torn, thinned, scarred or misaligned. Itshould be appreciated that the invention is not limited to particularspin sequences but may use any current or future MRI imaging modalitythat may be subsequently discovered.

From such diagnosis of tissue damage by the above method the suitabilityof various treatment modalities can be evaluated by medical professions,as well as verifying that the patient's complaints of pain are indeedreal, as they correlate with nerves that would be affected by thedamage. It should be understood that pain can result from either directdamage to soft tissue having sensitive nerve endings (nocioceptors) orbecause the trauma results in an unstable spine in which bones move andeffect various neuro-structure's, nerve roots and spinal cord leading topain.

FIG. 3 is a sagittal MRI to illustrate the normal healthy anatomy of thecervical spine, which the numbered arrows point to the following softtissue structure: 1. Normal apical ligament; 2. Anterioroccipitoatlantal membrane; 3. Anterior atlantoaxial membrane; 4.Anterior longitudinal ligament; 5. Tectorial membrane; 6. Duralreflection; 7. Posterior occipitoatlantal membrane; 8. Posterioratlantoaxial membrane; 9. Nuchal ligament; 10. Flaval ligaments; 11.Area of interspinous ligaments; 12. Supraspinous ligament.

FIG. 4-13 now illustrates selected combination of the imaging modesaccording to Table I that reveal's a variety of soft tissue damage inseveral patients. FIG. 4A is sagital x-ray frame of a first patientfacing forward in an upright neutral posture, while FIG. 4B is aphotograph of the patients posture at the time x-ray image of FIG. 4Awas acquired. FIG. 4C is the MRI in the same posture and orientation asthe X-ray in FIG. 4B, however as the spinal cord and ligaments are nowvisible the multiple herniated discs bulge outward. This is revealedindirectly by their compression of the spinal cord, as the white linesrepresenting the fluid surrounding the cord has thinned as the discherniations impinge upon it.

FIG. 5A is sagital x-ray frame of another patient facing forward, in anupright neutral posture while FIG. 5B is a photograph of the patientsposture at the x-ray frame of FIG. 5A was acquired. FIG. 5C is the MRIin the same posture and orientation as the X-ray in FIG. 4B, however theherniated discs are more severe than as in FIG. 4C, as the fluidsurrounding the cord is no longer visible at the disc herniations.

FIG. 6A is a sagital motion X-ray frame in which the patient is in aflexion posture, which FIG. 6B being the visual image of the patientwhen the frame of FIG. 6A was recorded. The MRI in FIG. 6C was recordedwith the T2 FSE spin sequence at the same flexion posture as FIG. 6A andnow shows both Anteriolisthesis (forward slipping) of C4-5 as indicatedby arrow 601 and a Torn Posterior Longitudinal Ligament at as indicatedby arrow 602.

FIG. 7A is a sagital motion X-ray frame in which the patient is in aflexion posture, which FIG. 7B being the visual image of the patientwhen frame of FIG. 7A was recorded. The MRI in FIG. 7C was recorded withthe T2 FSE spin sequence at the same flexion posture as FIG. 7A and nowshows both Anteriolisthesis of C4-5 at arrow 701 and disc/spinal cordcompression at arrows 702 and 703.

FIG. 8A is a sagital motion X-ray frame in which the patient is in anextension posture showing Retrolisthesis of C3-4 (backward slipping).The MRI image in FIG. 8C was recorded with a T2 FSE spin sequence andalso shows Retrolisthesis of C3-4 at arrow 801 as well as disc/spinalcord compression at arrows 802 and 803.

FIG. 9A is a sagital x-ray frame of a patient in an upright neutralposture and is marked as a template with the series of white lines forMRI slices orientation for coronal images of alar and transverseligaments. FIG. 9B is a photograph of the patients posture at the timex-ray image of FIG. 9A was acquired. FIG. 9C is the PD weighted MRIimage from the middle slice in FIG. 9B, with the arrow pointing to thetorn alar ligament.

FIG. 10A is a sagital motion x-ray frame with the patient in an uprightposture but in right rotation. FIG. 10B is a photograph of the patientsposture at the time x-ray image of FIG. 10A was acquired. FIG. 10A ismarked as a template with the series of white lines to show thepreferred axial slice orientation for acquiring PD weighted MRI imagesequences of axial spots at the craniocervical junction for assessmentof the transverse/alar ligament damage. FIG. 10C is the PD weighted MRIimage for the slice in FIG. 10A connected by the black arrow that pointsto it. The white arrow in FIG. 10C lines points to the torn transverseligament that is now revealed.

FIG. 11A is a sagital motion x-ray frame with the patient in an uprightneutral posture. FIG. 11B is a photograph of the patients posture at thetime x-ray image of FIG. 11A was acquired. FIG. 11A is marked as atemplate with the series of white lines to show the preferred axialslice orientation for acquiring a series of MRI's using a T2 FSE spinsequence axial spots at the craniocervical junction for assessment ofthe transverse/alar ligament damage. FIG. 11C is the corresponding MRIacquired with the patient in the same neutral posture as in FIGS. 11Aand 11B. The arrow in FIG. 11C points to the torn transverse ligament.

FIG. 12A is a sagital motion x-ray frame with the patient in an uprightflexion posture and is marked as a template with a series of black linesindicated the preferred MRI slice orientation for Axial spot of theintervertebral disc. FIG. 12B is a photograph of the patients posture atthe time x-ray image of FIG. 12A was acquired, FIG. 12C is the MRI usingGRE spin sequence and obtained at the lower slice in FIG. 12A with thearrow pointing to the region of severe disc herniation with spinal cordand nerve root compression.

FIG. 13A is a sagital motion x-ray frame with the patient in an uprightextension posture and is marked as a template with a series of blacklines indicated the preferred MRI slice orientation for Axial spot ofthe intervertebral disc. FIG. 13B is a photograph of the patientsposture at the time the x-ray image of FIG. 13A was acquired. FIG. 13Cis the MRI of the lower slice in FIG. 13B acquired with a GRE spinsequence wherein the arrow points to a region of severe disc herniationwith spinal cord and nerve root compression.

It should be understood that although the examples provided apply to thecervical spine the various embodiments of the inventive method areapplicable to other joints, elbow, knee and like joints with suspectedsegmental dysfunction.

In another embodiment of the invention it is desirable to recordabsolute posture in the x-ray motion sequence for optimal or exactpatient positioning for the subsequent MRI steps to optimize images ofpathoanatomy.

Such methods of reproducing the patient posture in the MRI stage includehaving the MRI technician or radiologist review the template X-rayimages and position the patient as close as possible by visualreferences. The visual reference can be to the anatomy of the x-ray, butis preferably to a photographic visual light image of the patientrecorded simultaneously with the x-ray frame, and generally presented asa smaller magnification image in the corner of the frame. Once the firstMRI is acquired at a slice orientation equivalent to the plane of thex-ray image the position of the patient can be adjusted slightly by eye.It is especially preferred that the x-ray and MRI images can be overlaidor fused to assist in making such a visual comparison.

Alternatively, the software described below for image analysis issoftware may be operative to direct the computer to compare the x-rayand first MRI to determine a goodness of fit of the hard bony anatomythat is visible in both. Once the goodness of fit meets a predeterminedlevel, further MRI imaging can be obtained while the patient maintainsthe same posture or joint position. Alternatively, when patient is foundto have pathology/segmental dysfunction in flexion motion x-ray, asimple goniometer to measure degree of flexion, can assist the MRItechnician to reproduce similar posture in MRI.

Additional embodiment of the invention include the partial or fullautomation of the process sequences using image recognition softwarethat is capable of performing may if not all of the steps describedabove.

In another embodiment of the invention the analysis is computer aided.The software will encompass using digitized grayscale recognition toautomatically access extreme misalignments, capture those images to useto direct proper patient positioning and proper guidance for DynamicUpright MRI imaging parameters. In other embodiments of the inventionsoftware will direct a general purpose computer or a digital signalprocessor or the like to use digital mensuration in reviewing the motionx-ray sequences to identify the exact images that have met threshold forclinical instability. In general, the software preferably enables theautomatic detection, when bony structures have breached a normalpositional threshold.

Software method 600 as shown in FIG. 14 in a first step 610, is theacquiring of a sequential plurality of digital x-ray images frames ofthe joint undergoing motion.

In step 620, each image frame from step 610 is analyzed to identity atleast one of perimeter and corners of each bony structure. Software toperform such analysis on grey scale x-ray images is commerciallyavailable.

Further, U.S. Pat. Nos. 5,974,165; 7,295,691; all of which areincorporated herein by references, provides further details on methodsof detecting bony and other structures in grey scale images by computermeans to provide a digital representation for further image processingand analysis described below. As is known in the art, the computermeans, or computing means, may include a computer or computer-likeobject which contains a display, and a processing circuit (e.g., amicrocontroller, microprocessor, custom ASIC, or the like) is coupled toa memory and a display. The display may include a display device, suchas a touch screen monitor with a touch-screen interface. The computer orcomputer-like object may include a hard disk, or other fixed, highdensity media drives, connected using an appropriate device bus, such asa SCSI bus, an Enhanced IDE bus, a PCI bus, etc., a floppy drive, a tapeor CD ROM drive with tape or CD media, or other removable media devices,such as magneto-optical media, ect., and a mother board. The motherboardincludes, for example, a processor, a RAM, and a ROM, I/O ports whichare used to couple to the image sensor, and optional specializedhardware for performing specialized hardware/software functions, such assound processing, image processing, signal processing, neural networkprocessing, etc., a microphone, and a speaker or speakers. Associatedwith the computer or computer-like object may be a keyboard for dataentry, a pointing device such as a mouse, and a mouse pad or digitizingpad. Stored on anyone of the above described storage media (computerreadable media), the system and method include programming forcontrolling both the hardware of the computer and for enabling thecomputer to interact with a human user. Such programming may include,but is not limited to, software for implementation of device drivers,operating systems, and user applications. Such computer readable mediafurther includes programming or software instructions to direct thegeneral purpose computer to performance in accordance with the systemand method. The memory (e.g., including one or more of a hard disk,floppy disk, CDROM, EPROM, and the like) stores x-ray and/or MRI images.

Further, U.S. Pat. No. 5,099,859, which is incorporated herein byreferences, teaches means for x-ray image acquisition of joints andcomputer aided characterization of joint abnormalities.

Further, other embodiment of the invention also contemplates alternatemeans of acquiring a digital representation of joints, and in particularthe spine, such as is disclosed in U.S. Pat. No. 6,028,907, which isincorporated herein by reference.

Further, it is preferable that the anatomical identity of each bonystructure identified and mapped in step 620 be determined. Thisdetermination can be manual, by presenting a subset of the images to aradiologist and request a name or other identity be provided for eachdiscrete bony structure identified in the process. For example, thesoftware can present the radiologist with a grey scale image onto whichis overlaid colored outlines or markers of the digital representation ofeach bony structure determined in step 620, and then prompt for theentry of a name for each structure as it is presented. Alternatively,the determination can be automated wherein the software is operative tomake additional calculation to determine a bone identity figure of meritby comparing the digital representation using at least one of formulasand properties in a reference table, and then identify the bone in thetable when the calculation yields the highest figure of merit. Suchcriteria for calculating a figure of merit in the reference table mayinclude, without limitation bone area, proximity of other structures,aspect ratio and the like.

Next in step 630, for each bone structure in each image a bone placementfigure of merit (FOM) is calculated to determine if the bony structureshave breached a normal positional threshold. Such a thresholdcalculation may include one or more calculations based on one or amatrix of multiple parameters that may include rotation, displacementand spacing either absolute or with respect to adjacent bones. The bonedisplacement figure of merit may also take into account widely availablediagnostic criteria for any condition. It would also incorporate the AMAGuides for impairment 5^(th) edition which define clinical instability.Thus, the higher the figure of merit, the more a bone is displaced fromits normal position.

After the calculations in step 630, it then possible to calculate, instep 640, at least one image pathology FOM from the bone displacementFOM for each bone in the image for which the FOM is being calculated.The image pathology FOM may be the raw sum of the bone placement FOM, ora weighted calculation thereof, and optional may only take into accountbone displacements that have breached a normal positional threshold.

Using the calculation of steps 630 and 640, it is then possible todetermine which x-ray frame show an abnormal pathology and thus directthe further steps of MRI acquisition. Further, to the extent the FOMcalculated uses a medical diagnostic criteria, it is possible to alsodetermine the named condition for the abnormal pathology for thedirection of MRI acquisition.

Ideally, in step 650 after an image pathology FOM is calculated for eachx-ray frame the frames showing the most abnormal pathology, via highimage pathology FOM, are selected. Optionally, the radiologist can viewthese frames in a manner that simultaneously displays the digitalrepresentation of the bone to confirm the accuracy thereof, as well asto select patient postures for MRI imaging. To the extent that thesoftware has misidentified or mischaracterized a bone position this canbe rectified manually by the radiologist by outline the correction boneposition, such as through a pen entry screen, a curser or pointingdevice and the like, the above FOM calculation re-performed. To theextent that the image pathology FOM has provided a diagnosis for thex-ray frames displace, the radiologist can confirm, update or revisethis result as appropriate for further MRI acquisition.

In step 660, the MRI parameters are determined for each patient posturethat the radiologist desires to investigate further, or alternativelythe MRI parameters can be determined independent of intervention usingthe postures that results in image frame with the highest imagepathology FOM. In this step the pathological diagnosis for the imageframe is compared with that in column 1 of Table 1, or a similar tablefor other disorders to select the MRI parameters in the correspondingrow.

In step 670, optionally a template is generated to image the regionssurrounding each bone with a high FOM in the selected image frame withan abnormal pathology FOM.

The result of step 670 can be either an image, such as FIG. 9A-13A, withmultiple lines shown for MRI slice orientation, or a digital instructionset for MRI acquisition with the MRI parameters being generated based onthe corresponding row in Table 1, as well as from the anatomicalfeatures that are identified in digital format from step 620.

It should be appreciated that optionally step 600 may includesgoniometric measurement of head or neck absolute position in each x-rayframe. This goniometric position of the patients posture is intended tobe highly reproducible when positioning the patient for the MRI, andwould thus also be includes in MRI instruction set that results fromstep 670.

Thus, in step 680 the MRI's are acquired per the MRI template of Step670, with the patient in the posture determined by the frames selectedin step 650.

The above process preferably creates or deploys the following data filesor data structure of which the content is described below:

For each frame in the series of dynamic x-rays images there is a digitalversion that is a Bit map or vector representation of image, that isphoton intensity versus position, as well as a frame reference indicatorso the frame can be indexed with respect to adjacent images in thesequence. Further, U.S. Pat. No. 6,799,06, which is incorporated hereinby reference, teaches additional means of automated image featureextraction and digitally representing cartilage structure in MRI imagesfor the purposes of accessing the disease state, which are generallyapplicable to bone structures as well as further steps of quantifyingthe damage to soft tissue that is ultimately imaged by MRI in step 680.

Within or associated with each referenced frame is a data record of theidentity of each bone structure detected by the image analysis processas well as a geometric representation of the bone as a series of atleast 3 coordinate points or vectors, which may represent corners or theperimeter.

Further associated with each bone in each image are bone pathology FOM,and optionally an identity for each bone, such a name, number orcombination thereof.

Further associated with each image frame is an image pathology FOM, anoptional image pathology diagnosis.

It should be understood that the digital reference to an image framedoes not preclude various data compression formats, such as JPEG, MPEGand the like, not does the reference to the calculation of imagepathology with respect to each x-ray frame mean that absolutely eachframe is analyzed, as it is expected to eliminate frame's that showlittle change or down select a smaller number of representative x-rayframes by pre-processing and other means to lessen the calculationburden.

To the extent that the MRI parameters are not determined manually afterstep 650, it is further desirable that the data file or record of imageframe selected for obtaining a corresponding MRI also have associatedtherewith the MRI acquisitions parameters, such as slice orientation,spin sequence parameters and the like as described above. Further, tothe extent that it is desirable to obtain multiple MRI at differentpostures, it is also desirable that the master patient data file containor associate these and other parameters to each x-ray frame of interest,meaning it has an identified pathology or serves as a normal statereferences subject to further MRI acquisitions.

Optionally, the data set for each image frame of interest also include aposture coordinate set which contains the goniometric measurement of oneor more external positions of a characteristic external anatomy thatwhen reproduced in the MRI chamber uniquely position the patient in thesame posture as the X-ray acquisition step. Of course it should beappreciated that another aspect of the invention is an imaging device ormachine that acquires both the x-ray and MRI images while the patient isseated or otherwise disposed in the same chamber of the device so as tominimize the posture reproducibility error. Such a generic MRI machine1500 is schematically illustrated in a plan section in FIG. 15A, thepatient 10, or a portion thereof is situated in zone or cavity 1501 tobe exposed to a magnetic field 1502 from the MRI magnet source 1505.Pick up coils are omitted from the figures for simplicity ofillustration, as are other components well understood to one of ordinaryskill in MRI technology. The MRI instrument 1500 having a cavity 1501for receiving a patient 10 that is open on two or more opposing sides,an x-ray source 1510 is disposed to irradiate a patent in the cavity1501 of the MRI from a first of the two or more open sides such that thespatial attention of x-rays by area x-ray detector 1515, disposed on aside opposite said x-ray source 1510 can continuously acquire aplurality of x-ray images of the patient during the initial phase oftheir movement as described above. Preferably a digital camera 1520simultaneously acquires visual images of the patient to aid in posturereproduction as described further below.

MRI machine 1500 also includes a control unit, power and imageprocessing unit 1530 connected in power and/or signal communication witheach of the MRI magnet source 1505, x-ray source 1510, x-ray detector1515 and preferably also the optional digital camera 1520.

However, since the x-ray image are acquired dynamically while thepatient move the limb or joint, there will still be a need reproduce aparticular position that corresponds to a posture that was held for amere instant during the course of the x-ray acquisition process.

FIG. 15B illustrates a configuration for tracking posture of a patient10, by placing marking 1541 and 1542 on select portion of the head, faceor neck. The marking can be imaged with the digital camera insynchronization with the dynamic x-ray frame acquisition, hence then byassociating each x-ray frame with image coordinates for the marking1541, 1442 and the like, the same posture can be verified by using thedigital camera and image analysis software to confirm the markings havethe same image coordinates.

In additional, for calculating bone pathology, bone identity and imagepathology FOM's it is desirable to utilize additional data files so thatcomparison can be made to a normal or nominal pathology and the FOMcalculated. Further to the extent that certain MRI imaging be conductedautomatically, it is also desirable that process 600 also identifyreference topography were desired to define the slice orientationprecisely, based on the first or any earlier acquired MRI after thepatient is placed in the designated posture.

In addition, there is a data file representing the information in Table1 and the like, so that the proper MRI conditions are selected based onthe abnormal pathology found in the particular image frames by theprocess 600. Data file for image pathology FOM calculation andcomparison for each bone in each image pathology that requires aparticular set of MRI imaging parameters

While the invention has been described in connection with a preferredembodiment, it is not intended to limit the scope of the invention tothe particular form set forth, but on the contrary, it is intended tocover such alternatives, modifications, and equivalents as may be withinthe spirit and scope of the invention as defined by the appended claims.

TABLE 1 MRI MRI Imaging parameters Image Patient plane or position(s) orSlice Imaging slice posture Slice orientation(s) thickness parametersNeutral If patient is Sagital Neutral Parallel to the cervical   3 mmT1, T2 Sagital found to spine, with stack FSE. When Motion X- have aloss of oriented thru the center necessary Ray clip the cervical andsides of the dens of Proton Findings lordosis, C2 Density straightening,weighted curve image if reversal, suspected buckling, ligamentous signsof damage. angulation or listhesis. Note: Axial Neutral Sliceorientation   3 mm GRE structures parallel to the that are endplateswith stack found and starting above, going can be thru and below theevaluated: endplates Ligaments found to stretch or fail are the anteriorlongitudinal ligament, posterior longitudinal ligament, ligamentumflavum, Facet capsular ligament, Interspinous ligament, supra spinousligament, Nuchal ligament, alar ligament, transverse ligament, apicalligament, tectorial membrane, posterior atlanto occipital membrane,posterior atlanto axial membrane Neutral Disc Space Axial Neutral Ifangulation is present,   3 mm GRE Sagital angulation slice thru thecenter of the disc. Split the difference of the angulation of upper andlower vertebral endplate's for slice orientation A-P open SuspectedCoronal at Neutral Slice orientation 2.8 mm Proton mouth alar, theapproximately 10-15 Density Motion X-ray accessory or craniocervicaldegrees posterior to the weighted Clips transverse junctionsuperior/posterior sequence ligament position of the tip of failure thedens of C2 A-P open Suspected Axial spot Neutral Slice orientation 2.8mm Proton mouth alar, or somewhat Density Motion X-ray transverseperpendicular to the tip weighted Clips ligament of the dens of C2,sequence failure starting above the foramen magnum to the middle of thebody of C2 1. Flexion Listhesis or Sagital Flexion Slice orientation(s)  3 mm sagital interspinous Flexion Parallel to the cervical motionfanning, spine, with stack X- angulation oriented thru the center rayconsistant and sides of the dens of clips with failure C2 of the PLL,Ligamentum flavum, facet joint capsule, interspinous ligament and nuchalor supraspinous ligament Flexion Sagital Flexion axial spot Sliceorientation Sagital Flexion when disc parallel to the motion pathologyfound endplates with stack X-ray such as starting above, going clipangulation, thru and below the protrusion/herniation endplates SagitalSagital Extension axial Slice orientation Extension Extension spot whendisc parallel to the motion X-ray pathology found endplates with stackclip such as starting above, going angulation, thru and below theprotrusion/herniation endplates Sagital Sagital Extension Parallel tothe cervical Extension Extension spine, with stack motion X-ray orientedthru the center clip and sides of the dens of C2

The invention claimed is:
 1. A medical imaging method for joints inliving creatures, the method comprising the steps of: a. acquiring adynamic sequence of x-ray images of at least one joint of a livingcreature over a range of motion, b. analyzing the dynamic x-ray imageframes to identify at least a location within one posture positionpresenting a possible abnormal pathology, c. determining MagneticResonance Imaging (MRI) parameters for imaging the possible abnormalpathology in greater detail than the x-ray images, d. acquiring at leastone series of multiple MRI images at positions and locations with thepotential abnormal pathology with said parameters wherein the MRIparameters include obtaining one or more MRI images at the same posturethat presented the possible abnormal pathology, wherein the MRI imagesin the at least one series are of parallel spaced apart planes in theliving creature, each spaced apart plane being separated from the mostadjacent spaced apart plane by a spacing of not more than 3 mm.
 2. Amedical imaging method for joints in living creatures according to claim1 wherein at least one joint is the human cervical spine and the livingcreature is a human being disposed in an upright posture.
 3. A medicalimaging method for joints in living creatures according to claim 2wherein the range of motion comprises at least one of flexion, extensionand rotation of the head and neck.
 4. A medical imaging method forjoints in living creatures according to claim 3 wherein said step ofacquiring a dynamic sequence of x-ray images and acquiring MRI images iscarried out in an instrument having a cavity for receiving a patientthat is open on two or more opposing sides, wherein an x-ray sourcedisposed to irradiate a patent in the cavity of the MRI from a first ofthe two or more open sides, and an x-ray detector disposed on a sideopposite said x-ray source for continuously acquiring a plurality ofx-ray images of the patient.
 5. A medical imaging method for joints inliving creatures according to claim 4 wherein said step of acquiring adynamic sequence of x-ray images and acquiring MRI images is carried outin an instrument further comprising a patient support surface whereinthe patient is in an upright position in the MRI cavity.
 6. A medicalimaging method for joints in living creatures according to claim 4wherein during said step of acquiring a dynamic sequence of x-ray imagesthe x-ray detector is operative to continuously acquire digital X-rayimages as discrete image frames for further analysis to determine MRIimaging parameters.
 7. A medical imaging method for joints in livingcreatures according to claim 1 wherein said step of acquiring a dynamicsequence of x-ray images is carried out in an instrument having means toreproducibly position the patient in the same posture for theacquisition of multiple MRI images in that posture.
 8. A medical imagingmethod for joints in living creatures according to claim 7 furthercomprising the step of reproducibly positioning the patient in the sameposture for the acquisition of multiple MRI images wherein the means toreproducibly position comprises a digital camera to simultaneouslyacquire visual image frames in synchronization with x-ray image frameswherein a posture coordinate set is determined from visual markersplaced on the patient.
 9. A medical imaging method for joints in livingcreatures according to claim 1 further comprising the step of markingone of more dynamic x-ray image frames are with multiple lines toidentify the parallel spaced apart planes for which the multiple MRIimages are acquired.
 10. A medical imaging method for joints in livingcreatures according to claim 1 wherein said step of analyzing thedynamic x-ray image frames further comprises the step of identifying thepossible abnormal pathology with a computing means.
 11. A medicalimaging method for joints in living creatures according to claim 10wherein during said step of identifying the possible abnormal pathologywith the computing means said computing means is further operative to:a) analyze a sequence of digital x-ray image of a joint of a livingcreature in motion to: i. identifying the boney structures in each imagein the sequence; ii. compare for each image in the sequence the relativeposition of at least one reference position on each bony structure withrespect to another reference position on each adjacent bony structure todevelop at least one relative displacement parameter of the referenceposition of each bony structure; iii. compare each relative displacementparameter for each boney structure against a nominal reference valuefrom a first reference table to develop a first figure of meritrepresenting the abnormality for each boney structure in each imageframe; iv. develop a second figure of merit for the abnormal pathologyof each image frame from the cumulative values of the first figure ofmerit associated with each boney structure in the image frame; b. selectat least one image frame based on the second figure of merit foracquiring one of more MRI images wherein the joint is in the sameposture as in the image frame selected from the second figure of merit;c. determine the MRI parameters for imaging the possible abnormalpathology in greater detail than the x-ray images.
 12. A medical imagingmethod for joints in living creatures according to claim 10 whereinduring said step of identifying the possible abnormal pathology with thecomputing means, said computing means is operative to analyze eachdigital x-ray image frame for determining MRI imaging parameters.
 13. Amedical imaging method for joints in living creatures according to claim10 wherein during said step of identifying the possible abnormalpathology with the computing means, the computing means is furtheroperative to compare the posture of a patient in one or more x-ray imageframes to at least one MRI image to confirm the patient has the sameposture in the X-ray images of interest before acquiring one or more MRIimages in that posture.
 14. A medical imaging method for joints inliving creatures according to claim 10 wherein during said step ofidentifying the possible abnormal pathology with the computing means,the computing means is operative to associate a posture coordinate setfor one or more X-ray image frames of interest to confirm the sameposture of the patient before acquiring multiple MRI images in thatposture.
 15. A non-transient computer-readable medium having storedthereon software that is operative to direct a general purpose computerto carry out the steps of: a. analyzing a sequence of digital x-rayimage of a joint of a living creature in motion to: i. identifying theboney structures in each image, in the sequence ii. comparing for eachimage in the sequence the relative position of at least one referenceposition on each bony structure with respect to another referenceposition on each adjacent bony structure to develop at least onerelative displacement parameter of the reference position of each bonystructure, iii. comparing each relative displacement parameter for eachboney structure against a nominal reference value from a first referencetable to develop a first figure of merit representing the abnormalityfor each boney structure in each image frame, developing a second figureof merit for the abnormal pathology of each image frame from thecumulative values of the first figure of merit associated with eachboney structure in the image frame, b. selecting at least one imageframe based on the second figure of merit for acquiring one of more MRIimages wherein the joint is in the same posture as in the image frameselected from the second figure of merit, c. determining the MRIparameters for imaging the possible abnormal pathology in greater detailthan the x-ray images from a third reference table.
 16. A non-transientcomputer-readable medium having stored thereon software according toclaim 15 that is further operative to mark one of more dynamic x-rayimage frames with multiple lines to provide a series of sliceorientations for the MRI imaging parameters.
 17. A non-transientcomputer-readable medium having stored thereon software according toclaim 15 that is further operative direct an MRI machine toautomatically acquire images at the MRI parameters.
 18. A non-transientcomputer-readable medium having stored thereon software according toclaim 15 that is further operative to confirm the joint is in the sameposture during a subsequent step of MRI imaging in at least one of thesame and a different MRI machine.
 19. A non-transient computer-readablemedium having stored thereon software according to 18 wherein the atleast one joint is the human cervical spine and the living creature is ahuman being disposed in an upright posture.
 20. A non-transientcomputer-readable medium having stored thereon software according to 15that is further operative to identify reference topograpy in MRI imagesthus acquired to define the slice orientation for additional MRI imagesto be subsequently acquired.
 21. A non-transient computer-readablemedium having stored thereon software according to claim 20 wherein therange of motion comprises at least one of flexion, extension androtation of the head and neck.